Low-voc aqueous coating compositions with excellent freeze-thaw stability

ABSTRACT

The present invention is an aqueous coating composition having excellent freeze-thaw stability and a low-VOC content. The aqueous coating composition of the invention includes at least one latex polymer derived from at least one monomer and at least one polymerizable alkoxylated surfactant, at least one pigment, and water. In accordance with the invention, less than 3.0% by weight of anti-freeze agents based on the total weight of the aqueous coating composition are used in the composition. The present invention also includes a method of preparing an aqueous coating composition such as a latex paint including the above components.

FIELD OF THE INVENTION

The present invention relates to the use of surfactants for reducing theVOC content of aqueous coating compositions such as paint and papercoating compositions while still maintaining the freeze-thaw stabilityof these compositions. In particular, the present invention relates tothe use of certain polymerizable alkoxylated surfactants in latexpolymers to reduce the VOC content of aqueous paint and paper coatingcompositions while maintaining the freeze-thaw stability of thesecompositions.

BACKGROUND OF THE INVENTION

Latex paints are used for a variety of applications including interiorand exterior, and flat, semi-gloss and gloss applications. In order toprovide latex paints with good film formation, coalescing agents areoften added to these paints. Exemplary coalescing agents include2,2,4-trimethyl-1,3-pentanediol monoisobutyrate (i.e. TEXANOL®commercially available from Eastman Chemical) and 2-ethylhexyl benzoate(i.e. VELATE® 378 commercially available from Vesicol Corporation).

In addition to coalescing agents, latex paints include anti-freezeagents to allow the paints to be used even after they have beensubjected to freezing conditions. In addition, anti-freeze agentstypically increase the open time for latex paints. Exemplary anti-freezeagents include ethylene glycol, diethylene glycol and propylene glycol.These anti-freeze agents are discussed in detail in “Antifreezes”,Ulmann's Encyclopedia of Industrial Chemistry, 5^(th) ed., vol. A3,pages 23-31.

The additives used as coalescing agents and anti-freeze agents areeffective for their purposes but are becoming more and more undesirablebecause they are volatile organic compounds (VOC's). After applicationof the latex paint to a substrate, the VOC's slowly evaporate into thesurroundings. As permissible VOC levels continue to decrease as a resultof increased environmental regulations, there has become a need in theart to produce latex paints with lower VOC levels. However, there isalso a need to maintain the performance of latex paints even at theselower VOC levels.

SUMMARY OF THE INVENTION

It has been discovered that the use of certain polymerizable alkoxylatedsurfactants in aqueous coating compositions reduces the need to includeanti-freeze agents in these compositions. In accordance with theinvention, aqueous coating compositions (e.g. latex paints) includingthese polymerizable alkoxylated surfactants can be produced havingexcellent freeze-thaw stabilities with the addition of little or noanti-freeze agents. The aqueous coating compositions of the inventioninclude less than 3.0% by weight and preferably less than 1.0% by weightof anti-freeze agents based on the total weight of the aqueous coatingcomposition. More preferably, the aqueous coating compositions aresubstantially free of anti-freeze agents. Therefore, aqueous coatingcompositions can be produced in accordance with the invention thatpossess lower VOC levels than conventional aqueous coating compositionsand thus that are more environmentally desirable.

The aqueous coating compositions of the invention include at least onelatex polymer derived from at least one monomer and at least onepolymerizable alkoxylated surfactant, at least one pigment, and water.The polymerizable alkoxylated surfactant used in the latex polymer hasthe structure:R¹—R²wherein R¹ is an allyl group selected from the group consisting ofCH₃—CH═CH— and CH₂═CH—CH₂—, and R² is a radical comprising at least twocarbon atoms and at least one oxyethylene or oxypropylene unit.Preferably, R² is —C₆H₃(R³)—(O—CH₂—CH₂)_(n)—R⁴,—O—CH₂—CH(CH₂—O—C₆H₄—R³)—(O—CH₂—CH₂)_(n)—R⁴, —(O—CH₂—CH₂)_(n)—R⁴,—(O—CH₂—CH(CH₃))n—R⁴, —(O—CH₂—CH₂)_(m)—(O—CH₂—CH(CH₃))_(n)—R⁴ or—(O—CH₂—CH(CH₃)),_(m)—(O—CH₂—CH₂)_(n)—R⁴; R³ is an alkyl group; R⁴ ishydroxy or a polar group such as sulfonate (—SO₃M), sulfate (—SO₄M),phosphonate (—PO₃M) or phosphate (—PO₄M); M is H⁺, Na⁺, NH₄ ⁺, K⁺ or Li⁺with the provision that R⁴ cannot be (—SO⁴M) or (—PO₄M) if R² is(O—CH₂—CH(CH₃))_(n)—R⁴ or —(O—CH₂—CH(CH₃))_(m)—(O—CH₂—CH₂)_(n)—R⁴;preferably R⁴ is hydroxy or (—PO⁴M), n is from about 5 to about 100; andm is from 0 to about 100. More preferably, R³ is C₇-C₁₃ alkyl (e.g.C₉H₁₉) and n is from about 5 to about 40.

In a preferred embodiment of the invention, the at least one pigmentincludes at least one pigment selected from the group consisting ofTiO₂, CaCO₃, clay, aluminum oxide, silicon dioxide, magnesium oxide,sodium oxide, potassium oxide, talc, barytes, zinc oxide, zinc sulfiteand mixtures thereof. More preferably, the at least one pigment includesTiO₂, calcium carbonate or clay. The at least one latex polymer in theaqueous coating composition can be a pure acrylic, a styrene acrylic, avinyl acrylic or an acrylated ethylene vinyl acetate copolymer and ismore preferably a pure acrylic. The at least one latex polymer ispreferably derived from at least one acrylic monomer selected from thegroup consisting of acrylic acid, acrylic acid esters, methacrylic acid,and methacrylic acid esters. For example, the at least one latex polymercan be a butyl acrylate/methyl methacrylate copolymer or a 2-ethylhexylacrylate/methyl methacrylate copolymer. Typically, the at least onelatex polymer is further derived from one or more monomers selected fromthe group consisting of styrene, α-methyl styrene, vinyl chloride,acrylonitrile, methacrylonitrile, ureido methacrylate, vinyl acetate,vinyl esters of branched tertiary monocarboxylic acids, itaconic acid,crotonic acid, maleic acid, fumaric acid, ethylene, and C4-C8 conjugateddienes. In addition to the above components, the aqueous coatingcomposition can include one or more additives selected from the groupconsisting of dispersants, surfactants, rheology modifiers, defoamers,thickeners, biocides, mildewcides, colorants, waxes, perfumes andco-solvents.

The present invention further includes a method of preparing an aqueouscoating composition, comprising the step of preparing the polymer latexbinder using emulsion polymerization by feeding monomers to a reactor inthe presence of at least one initiator and the at least onepolymerizable surfactant as described above and polymerizing themonomers and the polymerizable surfactant to produce the latex binder.The at least one pigment and other additives can then be mixed with theresulting latex binder to produce the aqueous coating composition. Thestep of preparing the polymer latex binder can include preparing aninitiator solution comprising the initiator, preparing a monomerpre-emulsion comprising monomers and the polymerizable alkoxylatedsurfactant of the present invention, adding the initiator solution to areactor, and adding the monomer pre-emulsion to the reactor. Theincorporation of the polymerizable alkoxylated surfactants in thepolymer latex enables the coating composition to have a lower VOCcontent while maintaining the freeze-thaw stability of the aqueouscoating composition at desirable levels.

These and other features and advantages of the present invention willbecome more readily apparent to those skilled in the art uponconsideration of the following detailed description, which describe boththe preferred and alternative embodiments of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following detailed description, preferred embodiments aredescribed in detail to enable practice of the invention. Although theinvention is described with reference to these specific preferredembodiments, it will be understood that the invention is not limited tothese preferred embodiments. But to the contrary, the invention includesnumerous alternatives, modifications and equivalents as will becomeapparent from consideration of the following detailed description.

The present invention is an aqueous coating composition having a low-VOCcontent but that has excellent freeze-thaw stability comparable toconventional aqueous coating compositions. The aqueous coatingcomposition of the invention includes at least one latex polymer derivedfrom at least one monomer and at least one polymerizable alkoxylatedsurfactant, at least one pigment and water.

The at least one latex polymer used in the aqueous coating compositionis preferably derived from monomers comprising at least one acrylicmonomer selected from the group consisting of acrylic acid, acrylic acidesters, methacrylic acid, and methacrylic acid esters. In addition, thelatex polymer can optionally include one or more monomers selected fromthe group consisting of styrene, α-methyl styrene, vinyl chloride,acrylonitrile, methacrylonitrile, ureido methacrylate, vinyl acetate,vinyl esters_of branched tertiary monocarboxylic acids (e.g. vinylesters commercially available under the mark VEOVA® from Shell ChemicalCompany or sold as EXXAR® Neo Vinyl Esters by ExxonMobil ChemicalCompany), itaconic acid, crotonic acid, maleic acid, fumaric acid, andethylene. It is also possible to include C4-C8 conjugated dienes such as1,3-butadiene, isoprene and chloroprene. Preferably, the monomersinclude one or more monomers selected from the group consisting ofn-butyl acrylate, methyl methacrylate, styrene and 2-ethylhexylacrylate. The latex polymer is typically selected from the groupconsisting of pure acrylics (comprising acrylic acid, methacrylic acid,an acrylate ester, and/or a methacrylate ester as the main monomers);styrene acrylics (comprising styrene and acrylic acid, methacrylic acid,an acrylate ester, and/or a methacrylate ester as the main monomers);vinyl acrylics (comprising vinyl acetate and acrylic acid, methacrylicacid, an acrylate ester, and/or a methacrylate ester as the mainmonomers); and acrylated ethylene vinyl acetate copolymers (comprisingethylene, vinyl acetate and acrylic acid, methacrylic acid, an acrylateester, and/or a methacrylate ester as the main monomers). The monomerscan also include other main monomers such as acrylamide andacrylonitrile, and one or more functional monomers such as itaconic acidand ureido methacrylate, as would be readily understood by those skilledin the art. In a particularly preferred embodiment, the latex polymer isa pure acrylic such as a butyl acrylate/methyl methacrylate copolymer ora ethylhexyl acrylate/methyl methacrylate copolymer derived frommonomers including butyl acrylate, ethylhexyl acrylate and methylmethacrylate. The latex polymer dispersion preferably includes fromabout 30 to about 75% solids and a mean latex particle size of fromabout 70 to about 650 nm. The latex polymer is preferably present in theaqueous coating composition in an amount from about 5 to about 60percent by weight, and more preferably from about 8 to about 40 percentby weight (i.e. the weight percentage of the dry latex polymer based onthe total weight of the coating composition).

The at least one polymerizable alkoxylated surfactant used to form thepolymer latex has the structure:R¹—R²wherein R¹ is an allyl group selected from the group consisting ofCH₃—CH═CH— and CH₂═CH—CH₂—, and R² is a radical comprising at least twocarbon atoms and at least one oxyethylene or oxypropylene unit. R² is—C₆H₃(R³)—(O—CH₂—CH₂)_(n)—R⁴,—O—CH₂—CH(CH₂—O—C₆H₄—R³)—(O—CH₂—CH₂)_(n)—R⁴, —(O—CH₂—CH₂)_(n)—R⁴,—(O—CH₂—CH(CH₃))_(n)—R⁴, —(O—CH₂—CH₂)_(m)—(O—CH₂—CH(CH₃))_(n)—R⁴ or—(O—CH₂—CH(CH₃))_(m)—(O—CH₂—CH₂)_(n)—R⁴; R³ is an alkyl group; R⁴ ishydroxy or a polar group such as sulfonate (—SO₃M), sulfate (—SO₄M),phosphonate (—PO₃M) or phosphate (—PO₄M); M is H⁺, Na⁺, NH₄ ⁺, K⁺ or Li⁺with the provision that R⁴ cannot be (—SO⁴M) or (—PO₄M) if R² is(O—CH₂—CH(CH₃))_(n)—R⁴ or —(O—CH₂—CH(CH₃))_(m)—(O—CH₂—CH₂)_(n)—R⁴;preferably R⁴ is hydroxy or (—PO⁴M), n is from about 5 to about 100; andm is from 0 to about 100. More preferably, R³ is C₇-C₁₃ alkyl (e.g.C₉H₁₉) and n is from about 5 to about 40. The term “alkyl” as usedherein includes linear and branched alkyl groups. Suitable surfactantsfor use in the invention include surfactants sold under the marksNOIGEN® RN and HITENOL® BC and are commercially available from Montello,Inc or the PLURIOL® A . . . R(E) grades from BASF AG. For example,NOIGEN® RN-10, HITENOL® BC-10, HITENOL® BC-20 and PLURIOL® A10 R can beused in the invention. The surfactant is typically present in theaqueous polymer dispersion in an amount from greater than 0 to about 5%by weight based on polymer weight, more preferably from about 0.5 toabout 3% by weight based on polymer weight.

As mentioned above, the aqueous coating composition includes at leastone pigment. The term “pigment” as used herein includes non-film-formingsolids such as pigments, extenders, and fillers. The at least onepigment is preferably selected from the group consisting of TiO₂ (inboth anastase and rutile forms), clay (aluminum silicate), CaCO₃ (inboth ground and precipitated forms), aluminum oxide, silicon dioxide,magnesium oxide, talc (magnesium silicate), barytes (barium sulfate),zinc oxide, zinc sulfite, sodium oxide, potassium oxide and mixturesthereof. Suitable mixtures include blends of metal oxides such as thosesold under the marks MINEX® (oxides of silicon, aluminum, sodium andpotassium commercially available from Unimin Specialty Minerals),CELITES® (aluminum oxide and silicon dioxide commercially available fromCelite Company), ATOMITES®) (commercially available from English ChinaClay International), and ATTAGELS®) (commercially available fromEngelhard). More preferably, the at least one pigment includes TiO₂,CaCO₃ or clay. Generally, the mean particle sizes of the pigments rangefrom about 0.01 to about 50 microns. For example, the TiO₂ particlesused in the aqueous coating composition typically have a mean particlesize of from about 0.15 to about 0.40 microns. The pigment can be addedto the aqueous coating composition as a powder or in slurry form. Thepigment is preferably present in the aqueous coating composition in anamount from about 5 to about 50 percent by weight, more preferably fromabout 10 to about 40 percent by weight.

The coating composition can optionally contain additives such as one ormore film-forming aids or coalescing agents. Suitable firm-forming aidsor coalescing agents include plasticizers and drying retarders such ashigh boiling point polar solvents. Other conventional coating additivessuch as, for example, dispersants, additional surfactants (i.e. wettingagents), rheology modifiers, defoamers, thickeners, biocides,mildewcides, colorants such as colored pigments and dyes, waxes,perfumes, co-solvents, and the like, can also be used in accordance withthe invention. For example, non-ionic and/or ionic (e.g. anionic orcationic) surfactants can be used to produce the polymer latex. Theseadditives are typically present in the aqueous coating composition in anamount from 0 to about 15% by weight, more preferably from about 1 toabout 10% by weight based on the total weight of the coatingcomposition.

As mentioned above, the aqueous coating composition includes less than3.0% of antifreeze agents based on the total weight of the aqueouscoating composition. Exemplary anti-freeze agents include ethyleneglycol, diethylene glycol, propylene glycol, glycerol(1,2,3-trihydroxypropane), ethanol, methanol, 1-methoxy-2-propanol,2-amino-2-methyl-1-propanol, and FTS-365 (a freeze-thaw stabilizer fromInovachem Specialty Chemicals). More preferably, the aqueous coatingcomposition includes less than 1.0% or is substantially free (e.g.includes less than 0.1%) of anti-freeze agents. Accordingly, the aqueouscoating composition of the invention preferably has a VOC level of lessthan about 100 g/L and more preferably less than or equal to about 50g/L. Despite the fact that the aqueous coating compositions of theinvention include little or no anti-freeze agents, the compositionspossess freeze-thaw stabilities at levels desirable in the art. Forexample, the aqueous coating compositions of the invention can besubjected to freeze-thaw cycles using ASTM method D2243-82 withoutcoagulation. The aqueous coating compositions can also pass a draw-downtest performed by the method discussed below. Furthermore, the aqueouscoating compositions of the invention exhibit good heat storagestability and exhibit Stormer viscosity increases of less than 15KU,more preferably of 10KU or lower, after being stored for 14 days at 50°C. by the method discussed below.

The balance of the aqueous coating composition of the invention iswater. Although much of the water is present in the polymer latexdispersion and in other components of the aqueous coating composition,water is generally also added separately to the aqueous coatingcomposition. Typically, the aqueous coating composition includes fromabout 10% to about 85% by weight and more preferably from about 35% toabout 80% by weight water. Stated differently, the total solids contentof the aqueous coating composition is typically from about 15% to about90%, more preferably, from about 20% to about 65%.

The coating compositions are typically formulated such that the driedcoatings comprise at least 10% by volume of dry polymer solids, andadditionally 5 to 90% by volume of non-polymeric solids in the form ofpigments. The dried coatings can also include additives such asplasticizers, dispersants, surfactants, rheology modifiers, defoamers,thickeners, biocides, mildewcides, colorants, waxes, and the like, thatdo not evaporate upon drying of the coating composition.

In one preferred embodiment of the invention, the aqueous coatingcomposition is a latex paint composition comprising at least one latexpolymer derived from at least one acrylic monomer selected from thegroup consisting of acrylic acid, acrylic acid esters, methacrylic acid,and methacrylic acid esters and at least one polymerizable alkoxylatedsurfactant; at least one pigment and water. As mentioned above, the atleast one latex polymer can be a pure acrylic, a styrene acrylic, avinyl acrylic or an acrylated ethylene vinyl acetate copolymer.

The present invention further includes a method of preparing an aqueouscoating composition by mixing together at least one latex polymerderived from at least one monomer and at least one polymerizablealkoxylated surfactant as described above, and at least one pigment.Preferably, the latex polymer is in the form of a latex polymerdispersion. The additives discussed above can be added in any suitableorder to the latex polymer, the pigment, or combinations thereof, toprovide these additives in the aqueous coating composition. In the caseof paint formulations, the aqueous coating composition preferably has apH of from 7 to 10.

The latex polymer including the polymerizable alkoxylated surfactants ofthe invention can be used in combination with other ionic or non-ionictype of surfactants that are either polymerizable or non-polymerizable,in the aqueous coating composition. In particular, the polymer latexbinder can be prepared using emulsion polymerization by feeding themonomers used to form the latex binder to a reactor in the presence ofat least one initiator and the at least one polymerizable alkoxylatedsurfactant of the invention and polymerizing the monomers to produce thelatex binder. The monomers fed to a reactor to prepare the polymer latexbinder preferably include at least one acrylic monomer selected from thegroup consisting of acrylic acid, acrylic acid esters, methacrylic acid,and methacrylic acid esters. In addition, the monomers can includestyrene, vinyl acetate, or ethylene. The monomers can also include oneor more monomers selected from the group consisting of styrene, α-methylstyrene, vinyl chloride, acrylonitrile, methacrylonitrile, ureidomethacrylate, vinyl acetate, vinyl esters_of branched tertiarymonocarboxylic acids, itaconic acid, crotonic acid, maleic acid, fumaricacid, and ethylene. It is also possible to include C4-C8 conjugateddienes such as 1,3-butadiene, isoprene or chloroprene. Preferably, themonomers include one or more monomers selected from the group consistingof n-butyl acrylate, methyl methacrylate, styrene and 2-ethylhexylacrylate. The initiator can be any initiator known in the art for use inemulsion polymerization such as ammonium, sodium or potassiumpersulfate, or a redox system that typically includes an oxidant and areducing agent. Commonly used redox initiation systems are describede.g., by A. S. Sarac in Progress in Polymer Science 24(1999), 1149-1204.

The polymer latex binder can be produced by first preparing an initiatorsolution comprising the initiator and water. A monomer pre-emulsion isalso prepared comprising at least a portion of the monomers to be usedto form the latex polymer, one or more surfactants, water, andadditional additives such as NaOH. The one or more surfactants in themonomer pre-emulsion include the polymerizable alkoxylated surfactant ofthe invention. The initiator solution and monomer pre-emulsion are thencontinuously added to the reactor over a predetermined period of time(e.g. 1.5-5 hours) to cause polymerization of the monomers and tothereby produce the latex polymer. Preferably, at least a portion of theinitiator solution is added to the reactor prior to adding the monomerpre-emulsion. Prior to the addition of the initiator solution and themonomer pre-emulsion, a seed latex such as a polystyrene seed latex canbe added to the reactor. The seed latex is used to obtain a uniformparticle size distribution and does not influence the freeze-thawstability of the paint. In addition, water, one or more surfactants, andany monomers not provided in the monomer pre-emulsion can be added tothe reactor prior to adding the initiator and adding the monomerpre-emulsion. The reactor is operated at an elevated temperature atleast until all the monomers are fed to produce the polymer latexbinder. Once the polymer latex binder is prepared, it is preferablychemically stripped thereby decreasing its residual monomer content.Preferably, it is chemically stripped by continuously adding an oxidantsuch as a peroxide (e.g. t-butylhydroperoxide) and a reducing agent(e.g. sodium acetone bisulfite), or another redox pair such as thosedescribed by A. S. Sarac in Progress in Polymer Science 24(1999),1149-1204, to the latex binder at an elevated temperature and for apredetermined period of time (e.g. 0.5 hours). The pH of the latexbinder can then be adjusted and a biocide or other additives added afterthe chemical stripping step.

The aqueous coating composition is a stable fluid that can be applied toa wide variety of materials such as, for example, paper, wood, concrete,metal, glass, ceramics, plastics, plaster, and roofing substrates suchas asphaltic coatings, roofing felts, foamed polyurethane insulation; orto previously painted, primed, undercoated, worn, or weatheredsubstrates. The aqueous coating composition of the invention can beapplied to the materials by a variety of techniques well known in theart such as, for example, brush, rollers, mops, air-assisted or airlessspray, electrostatic spray, and the like.

The present invention will now be further described by the followingnon-limiting examples.

EXAMPLE 1 (E1)

Example 1 illustrates the preparation of a polymer dispersion containing2.0% (weight percent of active material based on dry polymer weight)NOIGEN® RN-10 surfactant (commercially available from Montello, Inc.representing Dai-lchi Kogyo Seiyaku Co., Ltd.). NOIGEN® RN-10 surfactanthas the following structure:

A monomer pre-emulsion was prepared by emulsifying 264 parts water, 37.5parts CALSOFT® L-40 surfactant (a sodium linear or branched alkylbenzene sulfonate surfactant commercially available from PilotChemical), 20.0 parts NOIGEN® RN-10 surfactant, 15.0 parts NaOH solution(10% solution in water), 7.5 parts itaconic acid, 20 parts ureidomethacrylate, 511.2 parts n-butyl acrylate and 461.0 parts methylmethacrylate. The initiator solution was prepared by dissolving 2.5parts ammonium persulfate in 47.5 parts water. A 2-liter stirred glassreactor filled with 272.4 parts deionized water and 3.14 parts of a 33%polystyrene seed latex was purged with nitrogen and heated to 85° C.When the temperature was reached, the initiator solution wascontinuously fed into the reactor over 4.5 hours and the monomerpre-emulsion was continuously fed into the reactor over 4.0 hours. Thereaction was further allowed to continue for 30 minutes before beingcooled down to 60° C.

To further reduce the residual monomer level, a chemical stripping stepwas conducted. A peroxide solution was prepared consisting of 1.43 partsof t-butylhydroperoxide solution (tBHP, 70% in water) and 6.7 parts ofsodium acetone bi-sulfite solution (SABS) and fed to the reactor over 45minutes. After the addition of tBHP and SABS, the reactor was maintainedat 60° C. for 30 minutes before being cooled down to room temperature.The pH of the latex was adjusted to 8.3 with concentrated ammonia. Theresulting polymer dispersion had a solids content of 60.1% and adiameter of 280 nm by photocorrelation spectroscopy.

EXAMPLE 2 (E2)

Example 2 illustrates the preparation of a polymer dispersion containing2.0% (weight percent of active material based on dry polymer weight)HITENOL® BC-10 surfactant (commercially available from Montello, Inc.representing Dai-lchi Kogyo Seiyaku Co., Ltd.). HITENOL® BC-10surfactant has the following structure:

The ingredients and process used for synthesis were the same as used inExample 1 except 20.0 parts of HITENOL® BC-10 surfactant was usedinstead of NOIGEN® RN-10 surfactant. The resulting polymer dispersionhad a solids content of 60.5% and a diameter of 280 nm byphotocorrelation spectroscopy.

EXAMPLE 3 (E3)

Example 3 illustrates the preparation of a polymer dispersion containing2.0% (weight percent of active material based on dry polymer weight)HITENOL® BC-20 surfactant (commercially available from Montello, Inc.representing Dai-lchi Kogyo Seiyaku Co., Ltd.). HITENOL® BC-20surfactant has the following structure:

The ingredients and process used for synthesis were the same as used inExample 1 except 20.0 parts of HITENOL® BC-20 surfactant was usedinstead of NOIGEN®) RN-10 surfactant. The resulting polymer dispersionhad a solids content of 59.8% and a diameter of 280 nm byphotocorrelation spectroscopy.

EXAMPLE 4a (E4a)

Example 4a illustrates the preparation of a polymer dispersioncontaining 1.5% (weight percent of active material based on dry polymerweight) PLURIOL® A1OR (commercially available from BASF AG). PLURIOL®A10R has the following structure:

A monomer pre-emulsion was prepared by emulsifying 176 parts water, 73.3parts PLURAFAC® A-38 surfactant (C18-alkyl ethoxylate with 25 EO units,15% solution in water from BASF) 58.7 parts DISPONIL® FES 77 surfactant(sodium sulfonate of C12-C14-alkyl ethoxylate with 30 EO units,commercially available from Cognis, 30% solution in water), 16.5 partssodium hydroxide (10% aqueous solution), 16.5 parts PLURIOL® A10R, 5.5parts acrylic acid, 11 parts acrylic amide (50%), 8.25 parts itaconicacid, 88 parts Mhoromer 6844-0 (N-(-2-Methacryloyloxy-ethyl)ethyleneurea, 25% in MMA from Roehm, Darmstadt, Germany), 333 parts methylmethacrylate and 660 parts n-butyl acrylate. The initiator solution wasprepared by dissolving 2.75 parts ammonium persulfate in 52.25 partswater. A 2-liter stirred glass reactor filled with 340 parts deionisedwater and 3.3 parts of a 33% polystyrene seed latex was purged withnitrogen and heated to 85° C. When the temperature was reached, 10% ofthe initiator solution was added. After 6 minutes, the remaininginitiator solution was continuously fed into the reactor over 4.5 hoursand 4% of the monomer pre-emulsion was fed into the reactor over 40minutes. The rest of the pre-emulsion was continuously fed over 190 min,afterwards, 44.7 parts water were added. The reaction was furtherallowed to continue for 30 minutes. After cooling to 60° C., the latexwas partially neutralized with 6.6 parts concentrated ammonia.

To further reduce the residual monomer level, a chemical stripping stepwas conducted. 11 parts of t-butylhydroperoxide solution (tBHP, 10% inwater) and 14.6 parts of sodium acetone bisulfite solution (SABS) werefed synchronously to the reactor over 40 minutes. Afterwards, thereactor was maintained at 60° C. for 20 minutes before being cooled downto room temperature. The pH of the latex was adjusted to 8.5 withconcentrated ammonia. The resulting polymer dispersion had a solidscontent of 60.4% and a diameter of 235 nm by photocorrelationspectroscopy.

EXAMPLE 4b (E4b)

Example 4b illustrates the preparation of a polymer dispersioncontaining 3.0% (weight percent of active material based on dry polymerweight) PLURIOL® A10R. The ingredients and process used for synthesiswere the same as used in Example 5a except that 33 parts of PLURIOL®A10R were used instead of 16.5 parts. The resulting polymer dispersionhad a solids content of 60.5% and a diameter of 214 nm byphotocorrelation spectroscopy.

EXAMPLE 5 (E5)

Example 5 illustrates the preparation of a polymer dispersion containing1.5% (weight percent of active material based on dry polymer weight)PLURIOL® A10R (commercially available from BASF AG) and 2-ethylhexylacrylate as main monomer.

A monomer pre-emulsion was prepared by emulsifying 240 parts water, 39.6parts Arylsulfonat surfactant (15% solution in water), 9.0 partsPLURIOL® A10R, 4.8 parts. methacrylic acid, 282 parts methylmethacrylate and 313 parts 2-ethylhexyl acrylate. The initiator solutionwas prepared by dissolving 2.4 parts ammonium persulfate in 108 partswater. A 1.5-liter stirred glass reactor filled with 217 parts deionisedwater was purged with nitrogen and heated to 78° C. When the temperaturewas reached, 10% of the initiator solution and 1% of the monomerpre-emulsion were added. After 20 minutes, the remaining initiatorsolution was continuously fed into the reactor over 4.5 hours and thepre-emulsion was continuously fed over 4.0 hours. The reaction wasfurther allowed to continue for 10 minutes and cooled down to 65° C.

To further reduce the residual monomer level, a chemical stripping stepwas conducted. 2.4 parts of t-butylhydroperoxide solution (tBHP, 10% inwater) and 4.2 parts of Rongalit® C (BASF) solution were fedsynchronously to the reactor over 40 minutes. Afterwards, the reactorwas cooled down to room temperature. The pH of the latex was adjusted to8.0 with concentrated ammonia. The resulting polymer dispersion had asolids content of 50.9% and a diameter of 287 nm by photocorrelationspectroscopy.

COMPARATIVE EXAMPLE 1 (CE19)

Comparative Example 1 illustrates the preparation of a polymerdispersion containing 2.0% (weight percent of active material based ondry polymer weight) LUTENSOL® AP-10 surfactant (commercially availablefrom BASF Corporation). LUTENSOL® AP-10 has the following structure:

The ingredients and process used for synthesis were the same as used inExample 1 except 20.0 parts of LUTENSOL® AP-10 surfactant was usedinstead of NOIGEN® RN-10 surfactant. The resulting polymer dispersionhad a solids content of 61.15% and a diameter of 280 nm byphotocorrelation spectroscopy.

COMPARATIVE EXAMPLE 2 (CE2)

Comparative Example 2 illustrates the preparation of a polymerdispersion containing 2.0% (weight percent of active material based ondry polymer weight) IGEPAL® CA 877 surfactant (commercially availablefrom GAF Corporation). IGEPAL® CA 877 surfactant has the followingstructure:

The ingredients and process used for synthesis were the same as used inExample 1 except 20.0 parts of IGEPAL® CA 877 surfactant (70% activity)was used instead of NOIGEN® RN-10 surfactant. The resulting polymerdispersion had a solids content of 60.16% and a diameter of 280 nm byphotocorrelation spectroscopy.

COMPARATIVE EXAMPLE 3 (CE3)

Comparative Example 3 illustrates the preparation of a polymerdispersion containing 2.0% (weight percent of active material based ondry polymer weight) EMULGATOR® 925 S surfactant (commercially availablefrom BASF Corporation). EMULGATOR® 925 S surfactant has the followingstructure:

The ingredients and process used for synthesis were the same as used inExample 1 except 20.0 parts of EMULGATOR® 925 S surfactant (70%activity) was used instead of NOIGEN® RN-10 surfactant. The resultingpolymer dispersion had a solids content of 60.89% and a diameter of 280nm by photocorrelation spectroscopy.

COMPARATIVE EXAMPLE 4 (CE4)

Comparative Example 4 illustrates the preparation of a polymerdispersion without PLURIOL® A10OR. The ingredients and process used forsynthesis were the same as used in Example 5a except that no PLURIOL®A10R was used instead of 16.5 parts. The resulting polymer dispersionhad a solids content of 60.0% and a diameter of 293 nm byphotocorrelation spectroscopy.

COMPARATIVE EXAMPLE 5a (CE5a)

Comparative Example 5a illustrates the preparation of a polymerdispersion containing EHA as main monomer without PLURIOL® A10R. Theingredients and process used for synthesis were the same as used inExample 5a except that no PLURIOL® A10R was used instead of 9.0 parts.The resulting polymer dispersion had a solids content of 50.8% and adiameter of 300 nm by photocorrelation spectroscopy.

COMPARATIVE EXAMPLE 5b (CE5b)

Comparative Example 5b illustrates the preparation of a polymerdispersion containing n-butyl acrylate as main monomer with 1.5%PLURIOL® A10OR. The ingredients and process used for synthesis were thesame as used in Example 5a except that nBA was used instead of EHA andthe relative amounts of nBA and MMA were adjusted to get the same MFFTof the latex as in Example 5. The resulting polymer dispersion had asolids content of 50.8% and a diameter of 251 nm by photocorrelationspectroscopy.

Paint Formulation

The following flat paint formulation with a total VOC level of 50 g/Lwas used for evaluating paint performance for examples 1-3 andcomparative examples 1-3 Ingredients Parts by Weight Water 193.3PROXEL ® GXL¹ 2.0 Propylene Glycol 7.2 NATROSOL ® 330 Plus² 3.22-Amino-2-Methyl-Propanol (AMP-95) 1.0 TAMOL ® 1124³ 6.8 TRITON ® CF-10⁴3.0 FOAMASTER ® S⁵ 3.0 TIONA ® RCL-535⁶ TiO₂ particles 220.1 MINEX ® 4⁷171.2 ICECAP ® K⁸ 63.6 Water 123.5 FOAMASTER ® S 3.9 NOPCO ® DSX 2000⁹3.9 TEXANOL ®¹⁰ 2.0 POLYPHASE ® AF1¹¹ 6.0 Polymer Dispersion (60%solids) 337.7 Water 20.0The above components were mixed in the above order using a high-speeddisperser (Dispermat from VMA-Getzmann in Reichshof, Germany).¹PROXEL ® GXL is a biocide based on 1,2-benzisothiazolin-3-onecommercially available from Zeneca.²NATROSOL ® 330 Plus is hydroxyethylcellulose based polymer thickenercommercially available from Aqualon Specialties.³TAMOL ® 1124 is a low molecular weight, ammonium-based, hydrophilicpolymer dispersant comprising 50% solids and commercially available fromRohm and Haas.⁴TRITON ® CF-10 is a modified alkylaryl polyether surfactantcommercially available from Union Carbide.⁵FOAMASTER ® S is a defoamer based on a proprietary blend of esters,oils, and silica derivatives commercially available from HenkelCorporation.⁶TIONA ® RCL-535 TiO2 particles commercially available from MillenniumInorganic Chemicals.⁷MINEX ® 4 is a nepheline syenite extender commercially available fromUnimin Specialty Minerals.⁸ICECAP ® K is an anhydrous kaolin clay commercially available fromBurgess Pigment Company.⁹NOPCO ® DSX 2000 is a thickener commercially available from HenkelCorporation.¹⁰TEXANOL ® is a 2,2,4-trimethyl-1,3-pentanediolmono(2-methylpropanoate) coalescing agent commercially available fromEastman Chemical.¹¹POLYPHASE ® AF1 is a fungicide commercially available from G. R.O'Shea Company.Paint Formulation 2

The following flat paint formulation with a total VOC level of 0 g/L wasused for evaluating paint performance for examples 4 and comparativeexample 4 Ingredients Parts by Weight water 99.7 Natrosol ® 250 HR¹⁾ 1.1TKPP²⁾ 1.0 Proxel ® BD 20 1.6 Tamol ® 731³⁾ 3.8 Drewplus ® L 475⁴⁾ 2.2Minex ® 4 86.7 Omyacarb ® 10⁵⁾ 30.7 Ti-Pure ® R 941⁶⁾ 206.7 Diafil ®525⁷⁾ 8.7 Dispersion (60.0%-60.5%) 203.7 Acrysol ® RM 2020⁸⁾ 11.0Drewplus ® L 475 1.1 Nuocide ® N 40-D [404-D]⁹⁾ 3.8 Nopco ® DSX 1550¹⁰⁾1.1 water 35.9-37.6The ingredients were added with stirring in the order given in theformulation.¹⁾Hydroxyethylcellulose based thickener from Hercules Inc.²⁾BK Ladenburg, Ladenburg, Germany³⁾Sodium salt of a carboxylated polyelectrolyte, 25% solution in water,for use as dispersant from Rohm & Haas Co. Philadelphia, Pa, USA⁴⁾Defoamer from Ashland Chemical Co., Drew Industrial Division, Boonton,NJ, USA⁵⁾Calciumcarbonate filler, typical particle size 12 μm, Omya AG,Oftringen, Switzerland⁶⁾Titaniumdioxide slurry, 64.5% solids content, DuPont, Wilmington, De,USA⁷⁾Diatomeous earth filler from CR Minerals Co., Golden, Co, USA⁸⁾Polyurethane thickener, 20% solids content, from Rohm & Haas Co.Philadelphia, Pa, USA⁹⁾Biocide from Creanova, Piscataway, NJ, USA¹⁰⁾Nonionic rheology modifier from Cognis GmbH, Düsseldorf, GermanyPaint Formulation 3

The following flat paint formulation with a total VOC level of 0 g/l wasused for evaluating paint performance for example 5 and comparativeexample 5 Ingredients Parts by Weight water 99.7 Natrosol ® 250 HR 1.1Tetrapotassiumpyrophosphate 1.0 Proxel ® BD 20 1.6 Tamol ® 731 3.8Drewplus ® L 475 2.2 Minex ® 4 86.7 Omyacarb ® 10 30.7 Ti-Pure ® R 941206.7 Diafil 8.7 Dispersion (50.8%-50.9%) 241.8-242.2 Acrysol ® RM 202011.0 Drewplus ® L 475 1.1 Nuocide ® N 40-D [404-D] 3.8 Nopco ® DSX 15501.1Test Methods

Stormer Viscosity (in KU, Krebs Units): The Stormer viscosity wasmeasured according to ASTM D 562-81.

ICI Viscosity (in Poise): The high shear ICI viscosity was measuredaccording to ASTM D 4287-94.

Heat Storage Stability: The heat storage stability of the paints wastested by measuring the Stormer viscosity (KU) increase after storingthe paints in an 8 oz. glass jar for 14 days in a drying oven at 50° C.

Freeze-Thaw Stability: The high freeze-thaw stability of the paints wastested according to ASTM D 2243-82. The freezer temperature was set at−18° C. Stormer viscosities were measured after each freeze-thaw cycle,if the paint did not coagulate.

Draw-Down of Films: After the third freeze-thaw cycle, a draw-down ofthe paint was made on white sealed paper (Plain Leneta white paperchart) with a 7 mil (about 180 μm thickness) blade. A pass or failurenote was given based on the grit level in the dried paint film. A paintfilm with no or sporadic microcoagulum was rated a “pass” and a paintfilm with a large amount of coagulum was rated a “fail”. The ratinggives information on freeze-thaw stability of the paint to supplementthe Stormer viscosity measurement.

Paint Test Results

The test results of the flat paint formulations based on the laticesfrom Examples 1-5 and Comparative Examples 1-5 are summarized in Table 1below. TABLE 1 Example 1 Example 2 Example 3 Example 4a Example 4bExample 5 Stormer 86 87 76 97 98 105 Viscosity (KU) ICI Viscosity 0.640.65 0.54 1.0 1.1 1.2 (poise) Heat Storage 10 9 10 9 8 n.d. Stability(ΔKU:KU increase after 2 weeks at 50° C. Freeze-Thaw 96/94/89/91/9196/97/92/92/93 85/85/81/81/84 119/137/>140/>140/>140116/127/134/136/>140 120/118/120/121/126 Stability (KU after 1, 2, 3, 4,5 cycles) Grit in Draw Pass Pass Pass Down Films after 3 Freeze- ThawCycles Comparative Comparative Comparative Comparative ComparativeComparative Example 1 Example 2 Example 3 Example 4 Example 5a Example5b Stormer 80 72 76 90 109 106 Viscosity (KU) ICI Viscosity 0.78 0.630.72 1.1 1.2 1.2 (poise) Heat Storage 16 17 26 n.d. n.d. n.d. Stability(ΔKU:KU increase after 2 weeks at 50° C. Freeze-Thaw Fail after 1 Failafter 1 Fail after 1 Fail after 1 Fail after 1 Fail after 1 Stability(KU cycle cycle cycle cycle cycle cycle after 1, 2, 3, 4, 5 cycles) Gritin Draw Fail Fail Fail Down Films after 3 Freeze- Thaw Cycles

The test results in Table 1 show that the polymerizable surfactants ofthe present invention improve the freeze-thaw stability of the paints inwhich they are used compared to paints at equivalent VOC levels usingconventional, non-polymerizable surfactants. This is further evidencedby the reduced grit level in the latex paints produced using thesurfactants of the invention. Accordingly, the amount of anti-freezeagents used in the latex paints can be reduced when the polymerizablesurfactants of the invention are used in the manufacture of these paintswithout sacrificing the freeze-thaw stability of these paints.Additionally, freeze-thaw stability can be further enhanced by employingEHA as soft monomer as shown in Example 5. Latex paints produced usingthe surfactants of the invention also exhibit improved heat storagestability over latex paints using conventional additives. Furthermore,the surfactants of the invention allow latex paints to be produced withthe above-described properties at low or zero-VOC levels. Therefore, thelatex paints produced according to the invention are moreenvironmentally safe than conventional paints.

It is understood that upon reading the above description of the presentinvention, one skilled in the art could make changes and variationstherefrom. These changes and variations are included in the spirit andscope of the following appended claims.

1. A aqueous coating composition, comprising: (a) at least one latexpolymer derived from at least one monomer and at least one polymerizablealkoxylated surfactant having the structure:R¹—R² wherein R¹ is an allyl group selected from the group consisting ofCH3-CH═CH— and CH2=CH—CH2-, and R2 is a radical comprising at least twocarbon atoms and at least one oxyethylene or oxypropylene unit; (b) atleast one pigment; (c) water; and (d) less than 3.0% by weight based onthe total weight of the aqueous coating composition of anti-freezeagents.
 2. The composition according to claim 1, comprising less than1.0% by weight based on the total weight of the aqueous coatingcomposition of anti-freeze agents.
 3. The composition according to claim1, being substantially free of anti-freeze agents.
 4. The compositionaccording to claim 1, wherein R² is —C₆H₃(R³)—(O—CH₂—CH₂)_(n)—R⁴,—O—CH₂—CH(CH₂—O—C₆H₄—R³)—(O—CH₂—CH₂)_(n)—R⁴, —(O—CH₂—CH₂)_(n)—R⁴,—(O—CH₂—CH(CH₃))_(n)—R⁴, —(O—CH₂—CH₂)_(m)—(O—CH₂—CH(CH₃))_(n)—R⁴ or—(O—CH₂—CH(CH₃))_(m)—(O—CH₂—CH₂)_(n)—R⁴; R³ is an alkyl group; R⁴ ishydroxy or a polar group such as sulfonate (—SO₃M), sulfate (—SO₄M),phosphonate (—PO₃M) or phosphate (—PO₄M); M is H⁺, Na⁺, NH₄ ⁺, K⁺ or Li⁺with the provision that R⁴ cannot be (—SO⁴M) or (—PO₄M) if R² is(O—CH₂—CH(CH₃))_(n)—R⁴ or —(O—CH₂—CH(CH₃))_(m)—(O—CH₂—CH₂)_(n)—R⁴;preferably R⁴ is hydroxy or (—PO⁴M), n is from about 5 to about 100; andm is from 0 to about
 100. 5. The composition according to claim 4,wherein R³ is C₇-C₁₃ alkyl.
 6. The composition according to claim 4,wherein R³ is C₉H₁₉.
 7. The composition according to claim 4, wherein nis from about 5 to about
 40. 8. The composition according to claim 1,wherein the at least one pigment includes at least one pigment selectedfrom the group consisting of TiO₂, clay, CaCO₃, aluminum oxide, silicondioxide, magnesium oxide, talc (magnesium silicate), barytes (bariumsulfate), zinc oxide, zinc sulfite, sodium oxide, potassium oxide andmixtures thereof.
 9. The composition according to claim 1, wherein theat least one pigment includes TiO₂, calcium carbonate or clay.
 10. Thecomposition according to claim 1, wherein the inorganic pigment includesTiO₂.
 11. The composition according to claim 1, wherein the at least onelatex polymer is selected from the group consisting of pure acrylics,styrene acrylics, vinyl acrylics and acrylated ethylene vinyl acetatecopolymers.
 12. The composition according to claim 1, wherein the atleast one latex polymer includes a pure acrylic.
 13. The compositionaccording to claim 12, wherein the at least one latex polymer is derivedfrom at least one acrylic monomer selected from the group consisting ofacrylic acid, acrylic acid esters, methacrylic acid, and methacrylicacid esters.
 14. The composition according to claim 13, wherein the atleast one latex polymer is further derived from one or more monomersselected from the group consisting of styrene, α-methyl styrene, vinylchloride, acrylonitrile, methacrylonitrile, ureido methacrylate, vinylacetate, vinyl esters of branched tertiary monocarboxylic acids,itaconic acid, crotonic acid, maleic acid, fumaric acid, ethylene, andC4-C8 conjugated dienes.
 15. The composition according to claim 1,further comprising one or more additives selected from the groupconsisting of dispersants, surfactants, rheology modifiers, defoamers,thickeners, biocides, mildewcides, colorants, waxes, perfumes andco-solvents.
 16. A latex paint composition, comprising: (a) at least onelatex polymer derived from at least one monomer and at least onepolymerizable alkoxylated surfactant having the structure:R¹—R² wherein R¹ is an allyl group selected from the group consisting ofCH₃—CH═CH— and CH₂═CH—CH₂—; R² is —C₆H₃(R³)—(O—CH₂—CH₂)_(n)—R⁴,—O—CH₂—CH(CH₂—O—C₆H₄—R³)—(O—CH₂—CH₂)_(n)—R⁴, —(O—CH₂—CH₂)_(n)—R⁴,—(O—CH₂—CH(CH₃))_(n)—R⁴, —(O—CH₂—CH₂)_(m)—(O—CH₂—CH(CH₃))_(n)—R⁴ or—(O—CH₂—CH(CH₃))_(m)—(O—CH₂—CH₂)_(n)—R⁴; R³ is an alkyl group; R⁴ ishydroxy or a polar group such as sulfonate (—SO₃M), sulfate (—SO₄M),phosphonate (—PO₃M) or phosphate (—PO₄M); M is H⁺, Na⁺, NH₄ ⁺, K⁺ or Li⁺with the provision that R⁴ cannot be (—SO⁴M) or (—PO₄M) if R² is(O—CH₂—CH(CH₃))_(n)—R⁴ or —(O—CH₂—CH(CH₃))_(m)-13 (O—CH₂—CH₂)_(n)—R⁴;preferably R⁴ is hydroxy or (—PO⁴M), n is from about 5 to about 100; andm is from 0 to about
 100. (b) at least one latex polymer derived from atleast one acrylic monomer selected from the group consisting of acrylicacid, acrylic acid esters, methacrylic acid, and methacrylic acidesters; (c) at least one pigment; (d) water; and (e) less than 3.0% byweight based on the total weight of the aqueous coating composition ofanti-freeze agents.
 17. The paint composition according to claim 16,wherein R³ is C₇-C₁₃ alkyl.
 18. The paint composition according to claim16, wherein the latex polymer is a pure acrylic latex polymer.
 19. Thepaint composition according to claim 18, wherein the latex polymer is abutyl acrylate/methyl methacrylate copolymer.
 20. A method of preparinga aqueous coating composition, comprising the step of: mixing (1) atleast one latex polymer derived from at least one monomer and at leastone polymerizable alkoxylated surfactant having the structure:R¹—R² wherein R¹ is an allyl group selected from the group consisting ofCH₃—CH═CH— and CH₂═CH—CH₂—, and R² is a radical comprising at least twocarbon atoms and at least one oxyethylene or oxypropylene unit; and (2)at least one pigment; wherein the aqueous coating composition includesless than 3.0% by weight based on the total weight of the aqueouscoating composition of anti-freeze agents.
 21. The method according toclaim 20, wherein R² is —C₆H₃(R³)—(O—CH₂—CH₂)_(n)—R⁴,—O—CH₂—CH(CH₂—O—C₆H₄—R³)—(O—CH₂—CH₂)_(n)—R⁴, —(O—CH₂—CH₂)_(n)—R⁴,—(O—CH₂—CH(CH₃))_(n)—R⁴, —(O—CH₂—CH₂)_(m)—(O—CH₂—CH(CH₃))_(n)—R⁴ or—(O—CH₂—CH(CH₃))_(m)—(O—CH₂—CH₂)_(n)—R⁴; R³ is an alkyl group; R⁴ ishydroxy or a polar group such as sulfonate (—SO₃M), sulfate (—SO₄M),phosphonate (—PO₃M) or phosphate (—PO₄M); M is H⁺, Na⁺, NH₄ ⁺, K⁺ or Li⁺with the provision that R⁴ cannot be (—SO⁴M) or (—PO₄M) if R² is(O—CH₂—CH(CH₃))_(n)—R⁴ or —(O—CH₂—CH(CH₃))_(m)—(O—CH₂—CH₂)_(n)—R⁴;preferably R⁴ is hydroxy or (—PO⁴M), n is from about 5 to about 100; andm is from 0 to about
 100. 22. The method according to claim 21, whereinR³ is C₇-C₁₃ alkyl.
 23. The method according to claim 21, wherein R³ isC₉H₁₉.
 24. The method according to claim 21, wherein n is from about 5to about
 40. 25. The method according to claim 20, wherein the pigmentis at least one pigment selected from the group consisting of TiO₂,clay, CaCO₃, aluminum oxide, silicon dioxide, magnesium oxide, talc(magnesium silicate), barytes (barium sulfate), zinc oxide, zincsulfite, sodium oxide, potassium oxide and mixtures thereof.
 26. Themethod according to claim 20, wherein the pigment includes TiO₂, calciumcarbonate or clay.
 27. The method according to claim 20, wherein thepigment includes TiO₂.
 28. The method according to claim 20, whereinsaid mixing step comprises mixing at least one latex polymer selectedfrom the group consisting of pure acrylics, styrene acrylics, vinylacrylics and acrylated ethylene vinyl acetate copolymers.
 29. The methodaccording to claim 20, wherein the at least one latex polymer includes apure acrylic.
 30. The method according to claim 20, wherein the at leastone latex polymer is derived from at least one acrylic monomer selectedfrom the group consisting of acrylic acid, acrylic acid esters,methacrylic acid, and methacrylic acid esters.
 31. The method accordingto claim 30, wherein the at least one latex polymer is further derivedfrom one or more monomers selected from the group consisting of styrene,α-methyl styrene, vinyl chloride, acrylonitrile, methacrylonitrile,ureido methacrylate, vinyl acetate, vinyl esters of branched tertiarymonocarboxylic acids, itaconic acid, crotonic acid, maleic acid, fumaricacid, ethylene, and C4-C8 conjugated dienes.
 32. The method according toclaim 20, wherein said mixing step comprises further mixing at least oneadditive selected from the group consisting of dispersants, surfactants,rheology modifiers, defoamers, thickeners, biocides, mildewcides,colorants, waxes, perfumes and co-solvents.
 33. The method according toclaim 20, further comprising the step of preparing the polymer latexbinder using emulsion polymerization by feeding the at least one monomerto a reactor in the presence of at least one initiator and the at leastone polymerizable surfactant and polymerizing the monomers to producethe latex binder, wherein said mixing step comprises mixing the at leastone pigment with the resulting latex binder to produce the aqueouscoating composition.
 34. The method according to claim 33, wherein saidstep of preparing the polymer latex binder comprises: preparing aninitiator solution comprising the initiator; preparing a monomerpre-emulsion comprising the at least one monomer and the at least onepolymerizable surfactant; adding the initiator solution to a reactor;and adding the monomer pre-emulsion to the reactor.
 35. The methodaccording to claim 33, wherein said preparing step comprises feedingmonomers to a reactor comprising at least one acrylic monomer selectedfrom the group consisting of acrylic acid, acrylic acid esters,methacrylic acid, and methacrylic acid esters.
 36. The method accordingto claim 35, wherein said preparing step comprises feeding monomers to areactor further comprising one or more monomers selected from the groupconsisting of styrene, α-methyl styrene, vinyl chloride, acrylonitrile,methacrylonitrile, ureido methacrylate, vinyl acetate, vinyl esters ofbranched tertiary monocarboxylic acids, itaconic acid, crotonic acid,maleic acid, fumaric acid, ethylene, and C4-C8 conjugated dienes.
 37. Ina method for reducing the VOC content of an aqueous coating compositioncomprising a polymer latex, a pigment and water, without substantiallyreducing the freeze-thaw stability of the aqueous coating composition,the improvement comprising preparing the latex polymer used in theaqueous coating composition from at least one monomer and at least onepolymerizable alkoxylated surfactant, the at least one polymerizablealkoxylated surfactant having the structure:R¹—R² wherein R¹ is an allyl group selected from the group consisting ofCH₃—CH═CH— and CH₂═CH—CH₂—, and R² is a radical comprising at least twocarbon atoms and at least one oxyethylene or oxypropylene unit.
 38. Themethod according to claim 37, wherein R² is—C₆H₃(R³)—(O—CH₂—CH₂)_(n)—R⁴,—O—CH₂—CH(CH₂—O—C₆H₄—R³)—(O—CH₂—CH₂)_(n)—R⁴, —(O—CH₂—CH₂)_(n)—R⁴,—(O—CH₂—CH(CH₃))_(n)—R⁴, —(O—CH₂—CH₂)_(m)—(O—CH₂—CH(CH₃))_(n)—R⁴ or—(O—CH₂—CH(CH₃))_(m)—(O—CH₂—CH₂)_(n)—R⁴R³ is an alkyl group; R⁴ ishydroxy or a polar group such as sulfonate (—SO₃M), sulfate (—SO₄M),phosphonate (—PO₃M) or phosphate (—PO₄M); M is H⁺, Na⁺, NH₄ ⁺, K⁺ or Li⁺with the provision that R⁴ cannot be (—SO⁴M) or (—PO₄M) if R² is(O—CH₂—CH(CH₃))_(n)—R⁴ or —(O—CH₂—CH(CH₃))_(m)—(O—CH₂—CH₂)_(n)—R⁴;preferably R⁴ is hydroxy or (—PO⁴M), n is from about 5 to about 100; andm is from 0 to about 100.